Hi. On Thu, Feb 24, 2011 at 4:20 PM, Anthony Gerrard <anthonygerr...@gmail.com> wrote: > * I'm familiar with enterprise environments where you would have an "app > server" and a "database server" but are there any advantages to putting Zope > and MySQL on different servers?
Database servers (be it MySQL or ZODB) have different requirements than application servers (Zope). For small installations this generally doesn't matter, but if you have larger deployments you can adjust your hardware to fit the different roles. Database servers are generally disk I/O bound. Using the fastest possible and very reliable storage for these can help a lot. Be that either a RAID 1 or 10 of SAS drives with 10k or 15k rpm drives or a similar RAID of SSD's. Be prepared for some major performance degradation if you put your database on non-local NAS or SAN setups. Unless optimized correctly these will slow things down considerably. The ZODB has almost no CPU load, the SQL queries done by RelStorage also incur almost no CPU load. Memory isn't all too important for databases as long as the indexes fit into memory and you can handle savepoints / rollback data. Still some memory for the OS disk cache does help. Application servers are generally CPU bound and in case of Zope benefit a lot from memory for the connection cache. With RelStorage you can also use other cache setups like the shared memcached one. The disk types of application servers don't matter much and can be simple local disks, as there's no actual business data on the servers but just reproducible configuration setup - if you use proper version control for your code stored elsewhere that is. > * I'd expect a performance hit if we run Zope + MySQL on separate servers but > is this hit manageable? As long as the servers are on the same physical network with a low latency (~1ms) there's almost no overhead compared to running things locally. If you get into higher latencies of 10ms or more, you will see a noticeable drop in performance with Zope/Plone though. Hanno _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev